Clutch operator for phonograph tone arm drives



July 3, 1951 s. G. FALK v CLUTCH OPERATOR FOR PHONOGRAPH TONE ARM DRIVESFiled April 5, 1946 INVENTOR) ATTORNEY-5'.

Patented July 3, 1951 GLUTCH OPERATOR FOR PHONOGRAPH TONE ARM DRIVESSven Gustaf Falk, Stockholm, Sweden, assignor to Svcnska AktiebolagetPhilips, Stockholm, Sweden, a corporation of Sweden Application April 5,1946, Serial No. 659,810 In Sweden April 6, 1945 8 Claims.

The present invention refers to arrangements in gramophones havingautomatic record change in which the periodically operative drivingmember of a record changing and tone arm guiding mechanism is retardedat some moment of time in its function and the duration of the playingpause, i. e. the interval between the finished playing of a record andthe beginning of the playing of the following record, is regulated by accntrivance combined with the driving mechav nism of the gramophone anddriven by said latter mechanism, said contrivance being designed to forma step by step mechanism, the principal parts of which consist partly ofa push rod which is actuated, in one direction by spring tension, and inthe other direction by the driving mechanism, through the intermedium ofa driving member, partly of a stop member acting temporarily, which isarranged to impede the return of the push rod during the feeding processbefore a certain feeding position has been reached, from which the rodis returned by the spring tension.

The principal object of the invention is to simplify the design andnevertheless to ensure a thoroughly reliable engagement between thedriving member and the push rod, while at the same time an unintentionalreturn of the push rod during the feeding process is securely impeded bythe stop member.

The essence of the invention resides therein that the push rod is evenor practically even and that the driving member grasps the rod by meansof mutually opposite engaging edges or the like, which are so arrangedthat at a certain angular adjustment of the driving member they engagewith the rod and carry it with them in the feeding direction, and thatthe stop member, which likewise grasps the push rod and is provided withcorresponding engaging edges or the like, is adapted to stop, in acorresponding manner, the return movement of the rod in a certainangular position but to allow such a movement upon adjustment intoanother angular position.

Preferably the driving member and the stop member each consist of aplate or the like provided with holes for the push rod, which plate inone instance upon adjustment into a certain angular position relativelyto the rod engages with this latter and carries the same with it, and inthe other instance on account of its angular position relatively to therod stops the return movement of this latter but admits of such amovement upon adjustment into another angular position.

The driving member plate is actuated by a spring, which tends to adjustsaid plate into an inoperative position, in which it rests against anabutment and assumes a certain angular position relatively to the pushrod, feeding engagement with this rod being eifected by an impulsingmember, which is driven from the driving mechanism of the gramophone andtemporarily moves the plate into another angular position, in which therod is entrained.

The stop plate is held adjusted in a certain angular position relativelyto the push rod by a spring, against the action of which the plate ismoved into another angular position by a curve track combined with thecurve guide mechanism of the gramophone.

The starting position of the push rod may be regulated by means of aturnable eccentric or the like, the spring tension actuating the rodtending to maintain this latter in contact with said eccentric. However,there is nothing to prevent that a definitely selected starting positionis used for the rod and that, instead, the feeding stroke of said latteris varied.

An embodiment of the intended arrangement is illustrateddiagrammatically in the accompanying drawing, which shows a plan view ofthe parts contemplated by the invention.

The step by step mechanism consists, as mentioned above, in the firstplace of an even push rod I, which in suitable manner is slidablymounted in stationary bearings and is actuated by a spring 2, whichtends to maintain one end of the rod in contact with a stationaryeccentric 3 or the like. This eccentric is turnable for setting thestarting position of the rod I against the action of the spring 2. Therod I passes slidably through an abutment t, which is adjustable alongthe rod by means of a set screw 5 or the like. A spring 5 tends tomaintain a plate 1 or the like in contact with said abutment, which isperpendicular or substantiall perpendicular to the rod 5 so that alsothe plate tends to assume a perpendicular position. The plate I isprovided with a hole for the rod I, which hole is so proportioned thatthe plate may be inclined to the rod. The plate '5 is arranged for beingoperated from an impulsing member in the form of an eccentric t, or thelike, provided on an axle 9 mounted stationarily, on which is secured aworm wheel it meshing with a worm I I provided on the axle 52, whichdrives the turn table (only indicated by means of a dashed circle) ofthe gramophone. When the axle i2 rotates, the worm II and the worm wheelH3 transmit rotatory motion to the axle 9 so that the eccentric 8intermittently inclines the plate I which, as a result, cooperates withthe rod I for advancing this latter. The return movement of the rod I isimpeded during the advancement by the above-mentioned stop member, whichhas the shape of a plate I3 or the like, provided with a hole for therod I. The plate I 3 is actuated by a spring Ia, which tends to inclinethe plate relatively to the rod I by means of which in this way stoppingengagement is effected. For moving the plate I3 into perpendicular(inoperative) position relatively to the rod I there is provided a leverI5, which in turn is arranged for being operated froma curve track I6.This track is arranged in combination with a curve guide mechanismappertaining to the gramophone, which mechanism regulates the guidedmotions of the tone arm I? (only indicated by means of dashed lines) ofthe gramophone during the record changing operation. The curve guidemechanism and the curve track I6 are driven from the axle 12 through theintermedium of pinions I8, I9 and 29. The pinion has free motion on theaxle I2 and is provided with a 'fiange 2|, which carries a looking orcoupling pawl 22 actuated by a spring 23, which latter tends to move thepawl 22 into engagement with a toothed wheel 24 secured on the axle I2.When this engagement is present, the toothed wheel 24 entrains thepinion 21!, from which thus rotatory motion is transmitted to the curveguide mechanism and the curve track I 6. However, the coupling pawl 22may be released from the toothed wheel 24 by an arm 25 actuated by aspring 26 and provided with a gripping claw 21 or the like,

the arm 25 forms an abutment 23 which is situated right before the freeend of the push rod I.

The intended arrangement operates in the following manner:

When the gramophone is running, the eccentric 8 evidently actuates thedriving member plate I intermittently, whereby each time the push rod Iis endowed with a certain, though rather slight feeding. motion.However, during the playing ofa record this feeding motion isneutralized, inasmuch as in this instance the curve track I6 cooperateswith the lever I5 in such a manner that the stop plate I3 is heldadjusted in inoperative (perpendicular) position, whereby the spring 2.isallowed to return the push rod I to the starting position after eachtime when it has been endowed with a feeding impulse. When the playingof the record has been terminated in order to be followed by the recordchanging operation, and the curve track I5 has been turned into theposition shown in the drawing, the tone arm I! is located outside theedge of the record, besides which the gripping claw 21 of the arm 25engages with the pawl 22 so that this latter is released from thedriving toothed wheel 24. In consequence, the curve track It hasbeenbrought to a standstill in such a position that the lever I5 is releasedand the spring I4 is capable of inclining the plate I3 relatively to thepush rod I, which results in that surely the feeding motion of the rodis allowed but, on the other hand, not a return movement under theinfluence of the spring 2. From this follows that the push rod Iisadvanced from its starting position and finally actuates the abutment28 of the lever 25 so that the gripping claw 27 is raised outside thepath of motion of the coupling pawl 22 and said latter 4 engages thetoothed wheel 24. As a result, the curve guide mechanism is startedanew, the tone arm together with the needle microphone then being movedin an inward direction towards the record, and the needle being loweredtowards this latter for being played. According to the embodimentdescribed and illustrated, the period of time elapsing between theplaying of two records is influenced by the starting position, in whichthe push rod I is set by the aid of the eccentric 3, inasmuch as thepush rod will actuate the abutment 28 on the lever 25 at an earlier orlater point of time. By this, an accurate timing of the interval betweenthe termination of the playing of a record and the beginning of theplaying of the next record is rendered possible in a simple and reliablemanner. The eccentric 3 is secured on an axle, which preferably isprovided with a finger grip in the form of a pointer adjustable alongdifferent time marks, However, the invention is not limited to arealization according to which the duration of the above mentionedperiod of time is influenced by that starting position of the push rodI, which is set by means of the eccentric 3. Thus, there is nothing toprevent that the eccentric 3 is exchanged for a fixed abutmentwhichdetermines a definitely selected starting position for the rod I, thefeeding motion of which is, on the other hand, regulated in such a caseby varying the stroke of the feeding motion. This may, for instance, beeffected by adjusting the abutment 4 so that the cooperation of theeccentric 8 with the plate 1 is varied, i. e. becomes longer or shorterfor each feeding stroke, which results in that the rod I impinges on theabutment 28 at an earlier or later point of time. If desired, thisrealization, which, of course, is also contemplated by the invention,may be combined with the realization first described (the use of theadjustable eccentric 3).

Iclaim:

1. In an automatic record changing gramo phone a main drive member, aclutch device operable by said drive member, a control member operativein one position to render the clutch device inoperative, a rod movablelongitudinally in one direction to displace said control member to asecond position wherein said clutch device is operative, means normallytending to move the rod in the opposite direction, a stepping memberoperative when disposed in one angular position with relation to the rodto grip and displace said rod in the first mentioned direction, meansdriven by said drive member for periodically actuating the steppingmember to impart a succession of step-wise movements to said rod, acheck member operative when disposed in one angular position withrelation to the rod to grip and hold said rod against movement in thesecond mentioned direction, and means yieldably retaining the checkmember in said holding position;

2. An arrangement as claimed in claim 1 wherein the stepping and checkmembers are constituted by plates provided with Openings receiving saidrod, the edges of the opening in each plate being operated in saidangular position to enga e and grip said rod.

3. An arrangement as claimed in claim 1 provided with an abutment forsaid stepping member, and means operative between the periods ofactuation of the stepping member for moving the latter into engagementwith said abutment.

4. An arrangement as claimed in claim 1 provided with means for movinthe check member into a second angular position wherein said rod isfreely movable through said check member.

5. An arrangement as claimed in claim 1 provided with an adjustable stopfor variably limiting the longitudinal movement of said rod.

6. An arrangement as claimed in claim 1 provided with means coactingwith the stepping member for varying the amplitude of movement impartedthereto by the drive member, and means establishing a fixed position forlimiting the movement of the rod in the second mentioned direction.

7. An arrangement as claimed in claim 1 provided with an abutment forlimiting the movement of the stepping member, and means for adjustingthe position of said abutment.

8. An arrangement as claimed in claim 1 provided with means for variablylimiting the range of longitudinal movement of the rod, and means forvarying the amplitude of each stepwise movement of the stepping member.

SVEN GUSTAF FALK.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,430,780 Woodhull et a1 Oct. 3,1922 1,721,507 Calkins July 23, 1929 2,081,885 Runyan May 25, 19372,190,126 Jacobson Feb. 13, 1940 2,232,925 Mills Feb. 25, 1941 2,378,086Johnson June 12, 1945 2,421,835 Durant June 10, 1947

